Abstract

This study presents a novel technology to manipulate micro-particles with the assistance from flexible polymer-based optically-induced dielectrophoretic (ODEP) devices. Bending the flexible ODEP devices downwards or upwards to create convex or concave curvatures, respectively, enables the more effective separation or collection of micro-particles with different diameters. The travel distances of the polystyrene beads of 40 μm diameter, as induced by the projected light in a given time period was increased by ~100%, which were 43.0 ± 5.0 and 84.6 ± 4.0 μm for flat and convex ODEP devices, respectively. A rapid separation or collection of micro-particles can be achieved with the assistance of gravity because the falling polystyrene beads followed the inclination of the downward and upward bent ODEP devices.

Photographs and their corresponding schematic illustrations showing and explaining the manipulation of polystyrene beads with different sizes (20 and 40 μm) in the (a) flat, (b) convex (Media 1), and (c) concave configurations for the flexible polymer ODEP chips. The flexible polymer ODEP chip can be bent with positive or negative curvatures in appropriate time sequences to facilitate the manipulation of micro-particles.

(a) The measured maximum drag velocity (vd) and the induced ODEP force (FODEP) for 20 μm polystyrene beads in the flat flexible polymer ODEP chips, as induced by a light beam with a width of 20 μm, for four different light beams (the colors were red, green, blue and white). Note that the four light beams have the same light intensity (0.115 μW/cm2). (b) The average travel distance for 10 μm diameter polystyrene beads, after 1.5 sec, in the concave-shaped flexible polymer ODEP chips, as induced by a light beam with widths of 15, 20, and 25 μm, respectively.

The average travel distance for 10 μm polystyrene beads, after 1.5 s, in the convex and concave-shaped flexible polymer ODEP chips, induced by a 20 μm wide white light beam with different optical power 0.291, 0.477, and 0.551 μW/cm2, respectively.